We have developed a personal 3D videoconferencing system. A sender using the system can capture stereoscopic images from a stereo camera, encode them, and transmit them. The receiver can then receive the compressed data, decode it, and render the decoded images on a stereoscopic display. 3D video is useful for understand natural environments or scenes in which depth is important. The system mainly utilizes an autostereoscopic display, which is easy to use because it does not require glasses for stereoscopic views. The system enables users to share 3D telepointers, and it supports the creation of 3D graphical annotations by using telepointers, or by line drawing in 3D space. Finally, the system utilizes IPv4/IPv6 multicasting to exchange stereoscopic video, audio, and shared telepointer information among multiple sites.